I purchased these bearings along with the Tamiya 84399 Porsche 911 GT2 kit and they made the build feel like a complete fit and finish to the process. These bearings are highly necessary to decrease the wear and tear on these older TA02 parts and they will increase the overall life of the drivetrain parts on your chassis. I am using a brushless system in my TA02 and these bearings are a must if you do the same. I did a test with running two brushless TA02s; one with bearings and one stock. The one with bearings was not only faster but also had lower temperatures. A good sign!